To evaluate the reliability of a computer-assisted approach for automatically measuring ovarian follicles during controlled ovarian hyperstimulation (COH).Prospective, comparative study.Hospital Béclère, Clamart, France.Twenty-seven infertile IVF-ET candidates undergoing COH.Just before the oocyte retrieval, growing follicles (n=72) had their mean diameters measured and their volumes determined semimanually by virtual organ computer-aided analysis (VOCAL) and automatically by SonoAVC. Follicles were sorted in small (12-16 mm; n=35) and large (>16 mm; n=37) growing follicles. Measures were compared with the follicular fluid volume.Concordance of results using intraclass correlation coefficient and limits of agreement methods, respectively.Overall, VOCAL (median: 3.42 mL; range: 0.98-9.68 mL) and SonoAVC (3.25 mL; 0.98-8.63 mL) measurements were equivalent to the corresponding actual follicle volume (3.20 mL; 0.80-10.20 mL). The intraclass correlation coefficient values between follicular fluid volume and mean diameter, VOCAL, and SonoAVC were 0.51, 0.95, and 0.98, respectively, for small follicles, and 0.80, 0.93, and 0.92, respectively, for large follicles. 95% limits of agreement between actual volume and VOCAL (-1.09 to +1.07 mL) and SonoAVC (-1.08 to +0.84 mL) measurements were comparable in both groups.Automated measurement of multiple follicular volumes using SonoAVC is a simple technique, which reliability is superior to usual diameter measurements and comparable to VOCAL. This technologic refinement invites us to switch toward volumetric monitoring of follicle growth during COH.